Mathmetics

Q1.

Alok takes 8 more days than Bikas to finish a work. Alok and Bikas start the work and Bikas leaves the task 9 days before the work is finished. If Alok completes 75% of the overall work, how long would Alok have taken to finish the work if he had worked independently?

1)

8 days

2)

10 days

3)

12 days

4)

14 days

5)

None of these

Answer : 14 days Explanation : Let, Bikas takes x days to finish the work . So, Alok would take (x +8) days to finish the same work.

Given, Alok finishes 75% and Bikas finishes 25% work respectively.

So, (x+8)3/4 = (x/4)+9

or (3x+24)/4 = (x+36)/4

or 2x = 12

or x = 6

Therefore, Alok would finishes the work (6+8) = 14 days alone.

View Answer

Q2.

A fort has provisions for 250 soldiers for 35 days. After 5 days a reinforcements of 25 soldiers were arrived. Again after 10 days, 25 soldiers left the fort. How long will the remaining provisions lasting ?

1)

12

2)

16

3)

18

4)

19

5)

None of these

Answer : 19 Explanation :

Short- Cut Methods:

ND (No. of days) = N1D1 + N2D2 = total amount of food after 5 days.

or ( 250 X 30) = ( 250 + 25) X 10 + 250 X x

or x = 19 days .

View Answer

Q3.

Seven men and four boys can complete a work in 6 days. A man completes the double work than a boy. In how many days will 5 men and 4 boys complete the work ?

1)

4

2)

5

3)

6

4)

8

5)

None of these

Answer : None of these

View Answer

Q4.

Three men or eight boys can do a piece of work in 17 days. How many days will two men and six boys together take to finish the same work ?

1)

9 days

2)

11 days

3)

14 days

4)

12 days

5)

None of these

Answer : 12 days Explanation :

3 men = 8 boys

2 m = (8/3)x2 = 16/3 boys.

(2 men + 6 boys) = (16/2)+6 boys = 34/3boys

8 boys can complete the work in 17 days

or 34/3boys boys can complete the work in x days

or (34/3) : 8 = 17 : x

or x =(17x8x3)/34 = 12 days

View Answer

Q5.

10 man can finish a piece of work in 15 days. 8 women can finish the same work in 25 days. Only 10 women started working and in a few days completed a certain amount of work. After that 3 men joined them. The remaining work was completed by 10 women and 3 men together in 5 days . After how many did 3 men join with 10 women ?

1)

11

2)

13

3)

15

4)

10

5)

None of these

Answer : 13

View Answer

Q6.

16 men can complete a piece of work in 8 days. 20 women take 16 days to complete the same piece of work. 12 men and 10 women work together for 6 days. How many more days would 10 women alone require to complete the remaining piece of work ?

1)

6 days

2)

8 days

3)

10 days

4)

12 days

5)

None of these

Answer : 8 days Explanation : Given,16 men can complete a piece of work in 8 days while 20 women take 16 days to complete the same piece of work.

The ratio of the capacity of doing work i.e. men to women = (20 x 16 ) : (16 x 8) = 5:2

Therefore, remaining 1-3/4=1/4 part of the work done by only 10 women in =

Applying Chain Rule:

M1 x D1 x W2 = M2 x D2 x W1

or 20w x16 x 1/4 = 10w x D2 x 1

or D2 = 8 days

View Answer

Q7.

A,B,C can do a work in 36,54 and 72 days respectively.They started work together but A and B left the work 8 and 12 days before completion of the work respectively. Find the total number of days which the work has been completed ?

1)

15

2)

18

3)

24

4)

30

5)

None of these

Answer : 24 Explanation : Let,the total numbers of days requires to finish the job is x days.

So, A works for ( x-8) days and B works for (x-12) and C works for x days.

Therefore,

View Answer

Q8.

A and B can do a work together in 12 days while B and C together can do the same work in 15 days. If A is twice good work as C then, in how many days C can alone do the same work ?

1)

30 days

2)

36 days

3)

45 days

4)

60 days

5)

None of these

Answer : 60 days Explanation : Given, A+B can do the work in 1day =1/12 parts --- (I) :